ssh: add CryptoPublicKey interface, expose underlying crypto.PublicKey
When implemented by ssh.PublicKey types, the new CryptoPublicKey
interface exposes the public key in the the crypto.PublicKey form via a
CryptoPublicKey() method.
This is useful for example in a custom ServerConfig.PublicKeyCallback
function to check or record additional details about the underlying
crypto.PublicKey
Change-Id: I4429df42c6fc5119f7c0023a539aaa9c59648bba
Reviewed-on: https://go-review.googlesource.com/23974
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/ssh/keys.go b/ssh/keys.go
index ffcdb18..e13cf9c 100644
--- a/ssh/keys.go
+++ b/ssh/keys.go
@@ -281,6 +281,12 @@
Verify(data []byte, sig *Signature) error
}
+// CryptoPublicKey, if implemented by a PublicKey,
+// returns the underlying crypto.PublicKey form of the key.
+type CryptoPublicKey interface {
+ CryptoPublicKey() crypto.PublicKey
+}
+
// A Signer can create signatures that verify against a public key.
type Signer interface {
// PublicKey returns an associated PublicKey instance.
@@ -348,6 +354,10 @@
return rsa.VerifyPKCS1v15((*rsa.PublicKey)(r), crypto.SHA1, digest, sig.Blob)
}
+func (r *rsaPublicKey) CryptoPublicKey() crypto.PublicKey {
+ return (*rsa.PublicKey)(r)
+}
+
type dsaPublicKey dsa.PublicKey
func (r *dsaPublicKey) Type() string {
@@ -416,6 +426,10 @@
return errors.New("ssh: signature did not verify")
}
+func (k *dsaPublicKey) CryptoPublicKey() crypto.PublicKey {
+ return (*dsa.PublicKey)(k)
+}
+
type dsaPrivateKey struct {
*dsa.PrivateKey
}
@@ -509,6 +523,10 @@
return nil
}
+func (k ed25519PublicKey) CryptoPublicKey() crypto.PublicKey {
+ return ed25519.PublicKey(k)
+}
+
func supportedEllipticCurve(curve elliptic.Curve) bool {
return curve == elliptic.P256() || curve == elliptic.P384() || curve == elliptic.P521()
}
@@ -604,6 +622,10 @@
return errors.New("ssh: signature did not verify")
}
+func (k *ecdsaPublicKey) CryptoPublicKey() crypto.PublicKey {
+ return (*ecdsa.PublicKey)(k)
+}
+
// NewSignerFromKey takes an *rsa.PrivateKey, *dsa.PrivateKey,
// *ecdsa.PrivateKey or any other crypto.Signer and returns a corresponding
// Signer instance. ECDSA keys must use P-256, P-384 or P-521.
